For the time being I could fix the problem. Since I do not know what the implications are, it would probably still be better if one of you guys would take a look on it.

Line 654 and 655 are:

if ( true === $elapseDelay )

add_option( ‘disable_fsockopen’, $endDelay, null, true );

Since the forum works fine most of the time, I assume that add_option thing isn’t terribly important, so I just extended the if statement:

if ( true === $elapseDelay && function_exists(“add_option”))

Couldn’t see any negative side effects yet, but since this error only appeared sometimes this might be an illusion. In any way I have no idea what this is supposed to do in the first place, so it’s a bit of blind hacking…